Electric service plug



Fil ed June 22, 1932 I I .1: a. J 0 J 44 I Aer/Me 6f M0620) I JTA/YLEXfiFes/vcv/ 4 M'IE'ES/UENT INVENTORS ATTORNEYS '55 our invention;

Patented Aug. 21,

PATENT OFFICE ELECTRIC SERVICE PLUG Arthur S. McCloy, Detroit, Mich, andStanley F. French, Dobbs Ferry, N. )L, assignors to Anaconda; Wire &Cable Company, New York, N. Y., a corporation of Delaware u ApplicationJune 22, 1932, Serial No. 618,714

7 Claims. (01. 173-361) This invention relates to so-called service orattachment plugs adapted for use in leading electric current to varioushousehold appliances, such as electric refrigerators, radios, electrictoasters 6 and the like. Heretofore service plugs of this generalcharacter have been provided with terminal prongs extending generally inthe direction of length of the longitudinal axis of the plug, and theconnector cords or wires for carrying current to the terminal prongs ofsuch plugs have usually extended in the same general direction as theprongs. Plugs of this character are adapted to be engaged with wallreceptacles frequently secured to base boards or other parts of verticalwalls. When the conductor cords extend in the same direction as theterminal prongs, they are disposed practically perpendicular to the wallor base board and if such cords are to be run horizontally alongside ofthe wall from the plug, there is a tendency to injure the wire due tothe bending thereof. And when any strain is put on the conductor cord,there is a tendency to rock the plug as a whole, thus tending to loosenthe engagement of its prongs vwith the ooacting contacts of the usualwall receptacle.

Plugs heretofore used have been frequently made of moldable insulatingmaterial and when such material is struck by moving furniturethereagainst, there is a tendency to break the base of the plug.

Our improved plug aims to overcome the above and other features ofdisadvantage which are inherent in plugs heretofore used. One object ofour invention is to provide a plug in which 'the lead wire or conductorcord is disposed at an angle of substantially or approximately 90 to thedirection in which the terminal prongs of the plug extend. A furtherobject is to provide a service plug, the base of which is formed ofmoldable insulating material having a cap of resilientor cushioningmaterial, so as to minimize the chance of breakage when the molded baseis "struck by various articles of furniture and thellike. A furtherobject is to provide a plug in which. the connecting wires enter throughan aperture in the side wall of a chambered plug so that such wires neednot be given sharp bends in order to have them run along an adjacentbaseboard or wall.

" The above and further objects will be apparent from the followingspecification when read in connection with the accompanying drawing.

In the drawing- I Fig. 1 is a side elevation of a plug embodying Fig. 2is a view fromthe right side of Fig. 1, the cushion closure capbeingbroken away;

Fig. 3 is an inverted plan of Fig. 1;

Fig. 4 is a section on line 4-4 of Fig. 1;

Fig. 5 is a detail face view showing the base of our improved plug;

Fig. 6 is a section on line 6--6 of Fig. 5;

Fig. 7 is an elevation with parts shown in section of the improvedcushion closure cap forming part of the plug.

' Referring in detail to the drawing, 10 represents generally'the baseof the plug. This base is preferably formed of moldable insulatingmaterial such as hard rubber or its equivalent. It comprises an end wall12, a substantially cylindrical side wall 14 having a lateral extension16, which is provided with an aperture, as indicated at 18 for theentrance of the flexible conductor cord 20. s

Terminal prongs 22-22 extend through slots 24-24 formed in the end wall12, these prongs being adapted to engage the usual contacts of anysuitable form of wall receptacle. Each prong .22 has a pair of ears 26which receive rivets or studs 28, which are molded or otherwise embeddedin the end wall 12 of the insulating base. Each prong, carries asuitable terminal connecting means which in the embodiment illustratedcomprises a screw 30, having an enlarged head such as commonly used,this head being adapted to be screwed down on the end of the conductingwire, for example, as indicated in Fig. 2.

As indicated in Fig. 6, it is clear that the apertured lug 16 isdisposed substantially at a right angle to the longitudinal axis of thesubstantially cylindrical portion of the insulating base 14. Thus, theconductor cord 20 lies in a plane substantially parallel with the endwall of the base, this plane being perpendicular to the direction oflength of the-terminal prongs 22. This disposition of the parts, it willbe understood, provides an arrangement in which the conducting cord orwire is led through the opening in the side of the base, hence this cordcan lie close to or run along the adjacent wall or base board withoutinjuriously bending or straining the conductor.

The substantially cylindrical side wall 14 of the base provides achamber 32 for accommodating the terminal screws 30 and the ends of theconductor wires. This chamber is closed by a cap 34, preferably formedof live rubber, which is adapted to be tensioned over an annular bead 36formed on one extremity of the cylindrical wall 14: This cap, as bestshown in Fig. '7, is provided with an annular groove 38, which is formedby are- 119 entrant annular flange portion 40. The inner central portionof the cap 34 is thickened, as indicated at 42, thus forming an annularseat 44, which is adapted to abut the outer ring-like surface 46 of thecylindrical wall 14 of the base.

This cap, which is formed of live resilient rubber or similar material,serves a double function. It constitutes a neat detachable closure forthe chamber 32 formed on the base and it also serves as a resilientcushion to prevent breakage of the rigid base of the plug. This can,being formed of live rubber, has sufiicient elasticity so that it can betensioned over the annular bead 36, thus it forms a substantiallyhermetical seal. This fact, coupled with the fact that the exterior ofthe conductor. cord 20 makes a tight fit with the aperture 18 and thefact that the terminal prongs 22 make a tight fit with the slots 24,serves to exclude air from the interior chamber of the plug, thus ifthere is any short circuiting, air or other combustion supporting gasesare excluded and thus the fire hazard is lessened. The attachment plugdescribed is relatively inexpensive to manufacture.- The closure capbeing held in its place by its inherent elasticity requires noconnecting screws or other elements apt to be lost or misplaced whenmaking electrical connections with the prongs, this member being formedof live soft rubber provides a non-slip grip which is pleasing to thesense of touch. It has the further advantage of being non-conductingandalso physically isolated or out of contact with the conducting wiresso that persons about a household unfamiliar with the handling ofelectrical appliances may confidently grasp the same without fear ofreceiving an electric shock.

While we have described quite precisely the detailed features of theembodiment of the invention illustrated it is to be understood thatvarious modifications and substitution of equivalents may be made bythose skilled in theart without departure from the invention as definedin the appended claims.

What we claim is:-

1. An electricservice plug comprising a rigid base of moldableinsulating material formed with a chamber, terminal prongs extendingfrom a point within the chamber outwardly from one end of said base, aconductor extending through the base at an angle to said prongs andconnected to the latter within said chamber and an imperforate cap ofsoft elastic rubber or the like detachably embracing the end of saidbase opposite said prongs said cap having-an annular seat portionengaging the end of said base. a

2. An electric service plug comprising a rigid chambered base havingterminal prongs extending outwardly from the chamber thereof, said basehaving an aperture substantially at right angle to the direction oflength of said prongs, a conductor extending through said aperture andconnected to said prongs and an imperforate cap tensioned over an end ofsaid base and closing the chamber in said base.

3. An electrical service plug of the character described comprising arigid chambered base having a pair of terminal prongs extendingoutwardly therefrom, the base having a conductor aperture thereindisposed transversely to said prongs an annular bead on said base and animperforate cushion tensioned over said bead at the end of the baseopposite to that .end from which said prongs extend. a

4. An electrical service plug of the character described comprising abase of rigid insulating material having an end wall, a pair of terminalprongs projecting through slots formed in the end wall of the base,conductor connecting means secured to said prongs, a .side wall forming.part of the base and surrounding said connecting means, said side wallhaving a lateral conductor opening therein, and an imperforate cap ofelastic material'in detachable engagement with said side wall andclosing the end of the chamber formed by said end and side walls.

5. An electric service plug of the character described comprising arigidbase of insulating material having anend wall, a substantiallycylindrical side wall integral therewith and having a substantiallyradial conductor opening therein, terminal prongs secured to andprojecting through said end wall, an annular bead on said end wall andan imperforate closure cap of elastic material having an annular portionin engagement with said bead.

6. An electric service plug of the character described comprising a baseof rigid molded insulating material having an integral fiat end wall anda substantially cylindrical side wall, a lug extending laterallytherefrom and having a conductor aperture therein, terminal prongsextending through the end wall and an imperforate closure cap of elasticmaterial tensioned over the end of said side wall.

'7. An electric service plug comprising a base having an end wall and aside wall forming a chamber, a terminal prong piercing said end wall andhaving terminal connecting means within said chamber, alaterallyextending lug integral with said side wall and having a lateralaperture therein, a conductor-passing through said aperture connected tosaid terminal connecting means, and an imperforate detachable closurecap oftesilient material in tensioned engagement with said side wall.

a ARTHUR S. MCCLQY.

' STANIEY F. FRENCH.

